4.7.1 Interaction

All choices have an interaction style, controlled by the
:interaction initarg. The
radio-button-panel
and
check-button-panel
are simply
button-panels
with their interactions set appropriately. The interaction possibilities are listed below.

Set
:interaction
to
:single-selection to force single selection. Only one item may be selected at a time: selecting an item deselects any other selected item.

Set
:interaction
to the value
:multiple-selection to create a multiple selection choice element. This lets you select as many items as you want. A selected item may be deselected by clicking on it again.

Set
:interaction
to the value
:extended-selection to create an extended selection element. This is a combination of the other two: Only one item may be selected, but the selection may be extended to more than one item.

Set
:interaction
to the value
:no-selection
to force no interaction. Note that this option is not available for list panels. To display a list of items with no selection you should use a display pane instead.

Specifying an interaction that is invalid for a particular choice causes a compilation error.

The accessor
choice-interaction
is provided for inspecting a choice's interaction.